i know there were different models in different parts of the country. Our '80 Blazer was a hit in NJ because it had the stacked halogen headlights. They were not legal there at that time. And there is a California Special mustang I used to see around here. Apparently there were 3 models in that series that were all western. those were the days I spoze. now they are all the same. Haven't dug out the vin info yet for your manufacturing plant. later. busy busy.
Mary
I know my '73 was built at the Leeds plant in Kansas City. Haven't checked on my '76 yet. I see as many Sprint as El Caminos around here. The guy who runs my favorite salvage yard used to drive a Sprint, and said there was a dealership in Wichita that sold alot of them. So a big GMC dealership plus a short drive to Kansas City probably led to the situation here. But my '76 spent most of its life in Arizona. Maybe still built in Kansas City, I don't know. Might have even traveled on the same truck as yours, as they were both destined to be delivered "out west."